When a rectangular frame is presented with one of its edges on the subject's objective median plane, that edge is reported to be shifted to the side opposite to the rest of the frame (Roelofs, 1935). This effect is called the (original) Roelofs effect. When a target dot is presented within the same rectangular frame, an offset of the frame to one side of the subject's objective median plane cau...

Are the original Roelofs effect and the induced Roelofs effect confounded by the same expansion of remembered space? Roelofs (1935) first described a perceptual phenomenon in which an observer, when viewing a large rectangular frame whose center is positioned to the left or right of the objective midline, will underestimate the degree to which the frame is offset. More recently, Bridgeman, Peer...

We investigated whether the original Roelofs effect and the induced Roelofs effect are caused by the same shift in perceived straight ahead. Subjects were presented with a target within a frame in complete darkness. Target and frame could both be shifted to the left or right of objective straight ahead. On separate trials, subjects gave verbal estimates about the position of either the target o...

Distribution and origin of ozone in the eastern Mediterranean free troposphere during MINOS (August 2001) G.-J. Roelofs, B. Scheeren , J. Heland, H. Ziereis, and J. Lelieveld Institute for Marine and Atmospheric Research, Utrecht University, 3508 TA Utrecht, The Netherlands Institute for Atmospheric Physics, Deutsches Zentrum für Luftund Raumfahrt, Oberpfaffenhofen, Germany Max Planck Institute...

We distinguish two representations of visual space: a cognitive representation drives perception, and a sensorimotor representation controls visually guided behavior. Spatial values in the two representations are separated with the Roelofs effect: a target within an off-center frame appears biased in a location opposite the direction of the frame. The effect appears for a verbal measure (cognit...

The Roelofs effect is a distortion of perceived space that occurs when a large frame whose center is offset left or right from the objective midline is presented visually to an observer and causes a bias in the observer's subjective judgment of midline. Experiments were designed to test whether an isolated fragment (left or right end) of a Roelofs-inducing frame was capable of generating the Ro...

Thirteen relatively frequently collected species of baridine weevils from mainland China were mapped to improve our understanding of biogeographic patterns and distributional ranges of Baridinae in the Palaearctic and Oriental regions. This simple case study showed that taxonomists tend to underestimate the spatial scope required in regional investigations and descriptive works often resulting ...

Roelofs (2002) showed that by-item picture naming latencies in Santiago, MacKay, Palma, & Rho (2000) were linearly related to total number of segments across conditions, suggesting that structural effects of number of syllables and onset complexity might reect a confound with phonological length. However, Roelofs failed to test the statistical reliability of this relationship with structural f...